Method and apparatus for bulking synthetic fibers



Sept. 26, `1967 P. PARM-EGGIANI ET AL 3,343,240

METHOD AND APPARATUS FOR BULKING SYNTHETIC FIBERS Filed Dec. 22, 1964 v 6 Sheets-Sheet 1 sept. 26, 1967'A 3,343,240

METHOD AND APPARATUS FOR BULKING SYNTHETIC FIBERS P. PARMEGGIANI vET AL 6 Sheets-Sheet 2 Filed Dec.

Sept. 26, 1967 P. PARMEGGMNI ETAL 3,343,240

METHOD AND APPARATUS FOR BULKING `SYNTiE'lIC FIBERS Filed Dec. 22, 1964 -6 Sheets-Sheet :5

uw?. V' "fr n 1 12 413v m INVENTORS Sept. 26, 1967 P. PARMEGGIANI ET AL 3,343,240

METHOD AND APPARATUS FOR BULKING SYNTHETIC FIBERS Filed Dec. 22, 1964 6 Sheets-Sheet 4 ,vrfaerfy Spt.,26, 1967 P. PARMEGGIANI ET AL 3,343,240

METHOD AND APPARATUSFOR BULKING SYNTHETIC FIBERS Filed Dec.

GVSheets-Sheet' 5 /r V.//////V/// INVENTORS v/wmy/i/I/ infini/r Sept' 26, 1967 I P. PARMEGGIANI ET AL 3,343,240

METHOD AND APPARATUS FOR BULKING SYNTHETIQFIBERS 6 Sheets-Sheet 6 'Filed Deo'. 22, 1964 INVENTORJ` pom/o vwegy/ow/ United States Patent Office 3,343,240 Patented Sept. 26, 1967 3,343,240 METHOD AND APPARATUS FOR BULKING SYNTHETIC FIBERS Paolo Parmeggiani, Seveso, and' Domenico Nicita, Cesano Maderno, Italy, assignors t SNIA viscosa-Societ Nazionale Industria Applicazioni Viscosa S.p.A., Milan, Italy, a company of Italy Filed Dec. 22, 1964, Ser. No. 420,381 Claims priority, application Italy, Dec. 27, 1963, 26,587/ 63 12 Claims. (Cl. 28-1) It is an object of the present invention to provide a process and device for voluminization by means of continuous crimping of filaments, bundles of filaments and slivers of textile fibres, in particular of artificial textile fibres, such as fibres of cellulose esters or regenerated cellulose and synthetic fibres such as polyamides, polyesters, polyolefins, etc.

It is known to impart crimping to synthetic filaments by means of the tamping of the filaments in a crimping chamber. The resulting crimping is not satisfactory from the point of view of configuration and of the machinery employed, which presents inconveniences, among other things, in that the crimping depends on the action of mobile parts and which do not permit the absolute regularity of forwarding and delivering the yarn.

It is known from American Patent No. 3,036,357 to carry out the crimping of the yarns by feeding a bundle of filaments through a pipe by means of a hot feeder gas under pressure to a crimping chamber of which one wall is constituted by a moving surface. This surface may also be utilized as a conveyor of the mass of crimped yarn into a chamber for stabilizing the crimping. That system, however, is not wholly satisfactory because, among other things, it renders the handling and fixing of the yarn which is heaped up in bulk on the conveyor belt difficult and the device comprises mobile mechanical parts which can create inconveniences.

It is also known from Belgian Patent No. 613,495 to carry out the crimping by feeding in the same way a bundle of filaments by means of a stream of hot fluid within a crimping chamber in which it is gradually heaped up and compressed by the same feeder fluid that escapes laterally, in a controlled manner, through openings provided in the wall of the crimping chamber. But even that device is not quite satisfactory, not only owing to the imperfect fixing of the curled yarn, but also owing to the inconveniences that result from the presence of holes in the crimping chamber and from the necessity of controlling the discharge of the fluid from said holes; inaddition the fluid so discharged is not available for the compression and forwarding of the yarn and the crimping chamber must be rather lon-g because of the gradual accumulation of the yarn caused by the progressive elimination of the feeding fluid.

It has now been found that perfect crimping, with a considerable effect of voluminization and stability at all treatments to which the woven yarns are subsequently subjected, in particular dyeing treatments, can be obtained by means of a completely static apparatus and by an extremely simple process, thanks to the present invention. According to the invention, the single-filament or multi-filament yarns or bundles of yarns (which will be generically indicated in the present specification by the expression non-crimped yarn) are fed by -means of a fiuidunder pressure, which is preferably hot (which will be called forwarding uid) to at least one tubular space or dragging passageway. From said space, the said yarn with the said forwarding fluid is introduced into a chamber, called crimping chamber, which is closed and has a cross-section considerably larger than that of the dragging passageway, the yarn arranging itself in said chamber with a three-dimensional tortuous configuration depending on the expansion and on the slowing down of the forwarding gas and being accumulated therein and tamped to form a crimped and compressed yarn sliver that localizes in the proximity of the outlet of the crimping chamber. The forwarding fluid is discharged through the crimped yarn from the crimping chamber.

Subsequently the crimped yarn, whose crimping however is not yet stabilized, is forwarded to a stabilizing zone in which it is subjected to a thermal stabilizing action, preferably by means of external fluids. Preferably the yarn is kept in this zone as a cylindrical sliver or worm that is guided along a rectilinear or curvilinear path, as desired, by suitable guides which may also be advantageously utilized to guide the hot stabilizing fluid through the yarn.

The guides have also the effect of providing a frictional resistance, that opposes the forward movement of the yarn, regularizing it and facilitating the formation of the sliver. The yarn is then discharged in the shape of a worm and such worm can be straightened out to obtain the yarn, whichis then wound up. Alternatively the worm or the straightened yarn can be subjected to a further thermal treatment, for instance by means of fluids.

In a preferred embodiment of the invention, the yarn 4that constitutes the worm is stretched out and subjected to a determined tension under conditions of temperature and of moisture such as to acquire, when it is wound up on -a rigid support, a labile substantially non-crimped configuration and so as to maintain this configuration when it is unwound therefrom under the conditions of temperature and moisture of weaving rooms. Preferably, there are employed tensions of from 20 to 200 g./den., temperatures of from 30 to 100 C., a relative room humidity of from 60% to 70% for a duration of from 0.2 to 2.0 seconds. However under these conditions, the crimped yarn keeps its own crimping at a potential state and recovers it when it is dipped into a scouring or dyeing bath or if it is in anyway subjected to a conditioning treatment with steam or with hot Water.

With the system according to the present invention, a critical factor is the ratio between the sections and diameters (if, as usually happens, circular cross-sections are involved) of the dragging passageway and of the crimping chamber respectively. It should be noted that the dragging passageway may be much reduced in length and that it may even become merely a nozzle for introducing the dragging gas, that is to say, in practice, the orifice of an injector. The ratio between the cross-sections should be between 1/1.5 and 1/ 15 and preferably between l/ 3 and 1/ 6. Also the length of the crimping chamber which has considerable importance, should be between 10 mm. and 150 mm. and preferably between 20 mm. and mm.

To facilitate the formation of the sliver of crimped material in the proximity of the outlet of the crimping chamber, the latter may be provided with localized obstacles such as for instance a restricted cross-section at the outlet or in the proximity thereof or roughened surfaces provided close to said outlet. There may be provided means for the total or partial closing of the orifice of the crimping chamber, causing the formation of a sliver of crimped yarn at the beginning of the operation; whereafter said sliver is maintained after complete opening of said outlet of the crimping chamber and during the operation of the apparatus under predetermined conditions. As a rule the obstacles met by the yarn in traveling through the stabilizing zone, are sufficient to cause the formation of the sliver. It is not difficult, if the need arises, to block the forwarding of the yarn manually in any point for a short time at the starting of the operation.

Along the path of the yarn there may also be exerted upon said yarn mechanical actions to restrict, to facilitate or to adjust, as the case may be, the forwarding of said yarns.

The yarn may be preheated by any means (for instance by a uid), prior to being subjected to the action of the forwarding fluid. The gaseous iluids employed for preheating as well as for forwarding the yarn and possiblyif a distinct fluid is utilized for this purpose-for the stabilization of the crimping, may be gases or vapours, saturated or superheated, or mixture thereof. Preferably one employs hot air or steam or a mixture of both. It is also possible to provide a number of feeding conduits for different gaseous uids or a number of zones or outlet openings for the fluids. Hence the device according to the invention comprises: a crimping chamber; at least one passageway for dragging the yarn towards the chamber; means for dragging the yarn by means of at least one dragging uid within said passageway; said crimping chamber having a sufficient cross-section to permit the widening, the arrangement in tortuous conguration, the accumulation and crimping of the yarn to form a sliver; means for guiding the sliver formed along a predetermined path, said means being constituted by preferably rectilinear guides spaced apart in such a way as to produce the desired frictional resistance against the forwarding of the sliver; and means for thermally treating the crimped yarn to stabilize the crimping.

If such thermal treating means involve, as preferably is the case, the use of a stabilizing iiuid, said guides for the sliver are preferably shaped in such a manner as to permit the feeding and discharging of the stabilizing uid and the passage of it through the mass of yarn.

It is also possible to addto the device other devices suitably controlled for contrasting, facilitating or adjusting as the case may be, the forwarding of the tamped yarn.

Since the tamped yarn forms a comparatively coherent mass in the shape of a sliver, the process according to the invention conveniently provides the decomposition of said sliver, extracting therefrom the crimped yarn and restoring it to its own individuality, so that the yarn can be wound up on a suitable support, thus the apparatus according to the invention correspondingly provides means for carrying out said operation. As stabilizing uids it is possible to use hot gases such as air or superheated steam or saturated steam. If one desires to use a fluid, which generally is saturated steam, under pressure, the discharge of the sliver from the stabilizing zone may be provided with pressure sealing means such as conveniently applied rolls.

Said rolls might be mounted idle and might be rotated and displaced by the pressure of the yarn that tends to come out from the stabilizing space, under the pressure of the forwarding fluid.

From the earlier U.S. Patent No. 2,820,278 of the same applicant there are already known rolls that serve to close a tamping chamber for crimping the yarn, which are driven by the pressure of the tamped yarn or by other means. In such case said rolls serve to contrast the forwarding of the yarn and to create the pressure necessary for the tamping, which in the absence of those rolls would not take place. In the instant case the rolls though mechanically analogous to those previously described, are used for a different purpose, i.e. as sealing members for the steam under pressure that serves for the stabilization of the crimping. The rolls may also be controlled in such a way as to turn independently of the pressure of the yarn, with predetermined speed.

Owing to their different function however, instead of being controlled with a speed lower than that at which the yarn would emerge from the stabilizing zone in the absence of said rolls, it is convenient that they be rotated with a speed as closely as possible equal to that at which the yarn would issue if a pressure-steam sealing device were not necessary. This step is convenient not to disturb the predetermined mechanical conditions of the device which are independent of the particular means of stabilizing the crimping that has been chosen. This step, of course, should not prevent one from conveniently adjusting the speed at which said rolls are driven, according to the requirements of each case. In lieu of the rolls it is possible to employ other sealing devices such as a disc or a metal plate facing the external border of the disc in such a manner as to determine a tapered interstice.

The invention is applicable to non-crimped or slightly crimped continuous laments in general, but preferably to the filaments of synthetic linear polymers and still more preferably to filaments of nylon 6, namely to the polymer of caprolactam.

The invention will be more fully understood with reference to the accompanying diagrammatical drawings in which:

FIG. 1 represents a general diagram of the apparatus for carrying out the process according to the invention,

FIG. 2 is an enlargement of the portion marked a in FIGURE 1,

FIG. 3 is a section of FIGURE 2 taken along the line b-b of FIGURE 2,

FIG. 4 is a variant according to another operating example of the section of FIGURE 3,

FIGURES 5, 6 and 7 represent modification of FIG- URE 2,

FIGURES 8, 9 and 10 represent examples wherein there are provided sealing means and devices for controlling the discharge of the crimped yarn;

FIGURE 11 represents an example in which there are provided means for preheating the yarn to be crimped and FIGURES 12 and 13 illustrate the structure of the crimped yarn.

With reference to FIGURES 1 and 2, numeral 10 indicates a feed pipe or injector for a forwarding iluid under pressure, preferably air or another cold or hot gas, or saturated or superheated steam. The numeral 11 represents a thread-crimping chamber. The numeral 12 indicates an orifice coaxial with the pipe 10, in communication with a dragging passageway having a restricted crosssection 13.

Under the influence of the kinetic energy of the forwarding uid, coming from the injector 10, the thread 14 is unwound from one or more bobbins 15, passes over the thread-guide 16 and is projected through the orice 12 and the passageway 13 into the curling chamber 11. The distance between the pipe 10 and the orifice 12 is adjustable in such a way as to obtain an optimum yield. At the outlet of the passageway 13 the fluid entering the chamber 11 expands thereby causing the slowingdown of the dragged thread which, as a consequence of such slowing-down, undergoes de-orientation and compression.

The pressure upon the compressed mass of yarn, due to the pressure of the forwarding fluid, produces the formation of a sliver 20 through which the forwarding fluid is discharged and provides the forwarding of the sliver within a stabilization zone 17 in which it is guided by suitable guides 18 (FIG. 2).

The sliver, leaving the stabilizing zone 17, passes through a comb 19 provided with three or more threadguides 21 which stretch it out-so to say-thereby causing the yarn to emerge from the compressed mass and to recover its own shape, while maintaining however the acquired crimping. The thread then passes over the rolls 23 and 24 and with the aid of the device 25 for distributing the yarn, it is Wound up on the bobbin 26.

In the embodiment of FIGURE 2, the feed pipe 10 and the passageway 13 are mounted in a block 27 that also carries the initial part yof the crimping chamber 11. The

stabilizing space 17 is defined by guides 18, preferably four in number, which conveniently join towards the discharge forming an outlet mouth 28.

The spaces 29 between the guides 18 permit the admission and the discharge of the stabilizing fluids. The stabilizing space is surrounded by a heated jacket 30.

A fluid-preferably air or another hot gas, or steam, saturated or superheated-enters the jacket from the conduit 31 and leaves from the conduit 32 provided with a valve 33, thereby heating the space 17 and effecting the stabilization of the crimping. To increase the effect of the stabilizing uid and to cause a direct contact between said fluid and the sliver, the guides 18 have preferably the structure illustrated in FIG. 3 or 4, which diagrammatically represent a section of FIG. 2 taken along the line b--b and a variant thereof.

In said FIGURES 3 and 4 there is represented the heating jacket 30 and the conduits 31 and 32 respectively for entry and output of the stabilizing iiuid. In FIGURE 3 there are four guides 18; in FIGURE 4 there are only three. A perforated cylinder 34 is connected to the guides 18, two of which are also connected to the jacket 30 by supports 38 and 39. Said cylinder 34 is provided with a plurality of holes 35 over its whole surface. The supports 38 and 39 divide the inner space of the jacket into two chambers 36 and 37, the passage from one to the other taking thus place through the sliver of yarn. The stabilizing fluid coming from the conduit 31 then penetrates into the chamber 36, wherefrom it passes into the space 17 through the holes 35 of the cylinder 34, passes through the mass of the sliver, and leaves through the holes 35 at the opposite side of the cylinder 34 within the chamber 37, from which it is -discharged through the conduit 32 and the valve 33. The diameter of the sliver 20 in the stabilizing space 17 is determined by the guides 18 and is preferably not very different from the inner diameter of the chamber 11. A possible small restriction of the space available to the sliver by way of the guides 18 may serve, if wanted, to increase the resistance against the forwarding of the yarn, but when there is no indication of the contrary in the examples, no restriction is supposed to take place.

FIG. 5 is a variant of the device according to FIG. 2, wherein the heating of the sliver for stabilization is effected by heating the guides 18 electrically by means of any electric resistor not shown, which is fed, for instance, by an electric circuit provided with a transformer 64.

FIG. 6 represents an analogous device wherein an auxiliary hot fluid under pressure is fed through a conduit 40, to a space 41 terminating in a tubular passageway 42 preceding the crimping chamber 11. Said auxiliary iiuid when discharging through the mass of yarn and the sliver 20, not only contributes to the forwarding and to the compression of the yarn, but also contributes to the stabilizing action.

FIG. 7 shows a preferred shape of the crimping chamber 11 having at its beginning, namely in the zone of initial expansion and at the point where the de-orientation and three-dimensional arrangement of the thread takes place, an expansion 43 that permits the thread a greater freedom to arrange itself in a tortuous configuration, almost forming an expanded mass with respect to the subsequent compressed mass.

In all the devices described, the outlet 28 of the stabilizing space can be--contrary to what has been said in the preceding examples-partly obstructed by a device rotating as diagrammatically represented in FIGURE 8. In this case, the closing takes place through two rolls 44 and 45 of which one may be driven and the other one idle. The r-olls are arranged in such a way as to close the outlet 28 formed by the joined guides 18. A motor 46 drives the roll 45 as well as the roll 47 that regulates the speed of the bobbin 26 for winding-up the crimped yarn and the roll 48 for regulating the delivery of the yarn 14 not yet crimped, at the inlet of the crimping device. The speeds of the transmissions 49, 50 and 51 from the motor 46 to the roll 45, and to the rolls 47 and 48 are adjustable by means of speed-regulators not represented in the figure so as to ensure the speed according to the desired crimping.

The roll 44 is fixed to one end of an arm 52, While the other end is fixed for'rotation, by means of a pin 53, to the device 54. A spring 55 presses the idle roll 44 against the driven roll 45 in such a way as to provide a sealing for the stabilizing fiuid fed into the stabilizing zone through the conduit 31.

Since however this device per se does not form part of the present invention, other different or similar types may be applied such as for instance those described in the U.S. Patent No. 2,820,278 of the same applicant, or such as a single roll of larger diameter, or any other suitable device.

As already described, the sliver or compressed thread is unwound -or loosened by passing over thread-guides 20, 21 and 22, and is wound up on the bobbin 26.

FIGURE 8 also shows another variant of embodiment of the invention. In the preceding examples, the pipe 10 for the feeding of the forwarding fluid was separated from the dragging conduit 13, i.e. the yarn 14 was subjected to the uid in the open air. This variant or embodiment shows an overpressure chamber 56 surrounding this part of the apparatus, thereby separating the nozzle of the pipe 10 and the orifice 12 of the conduit 13 from the surrounding air.

This Variant of the apparatus has two advantages. Since the input opening 57 for the thread 14 is very narrow, the fluid coming from the pipe 10 creates in the chamber 56 an overpressure that prevents the entrance of surrounding air and so prevents the contact 'between the thread and oxygen in the heating stage. At the same time, there are avoided useless losses of heat and the temperature of the liuid to be sent into the apparatus can be noticeably lowered-from 30 C. to 80 C. according to the conditions of the process and to the type of thread to be crimped.

Another embodiment represented in FIGURE 1l, shows as a possible variant applicable to any type of apparatus according to the invention, the insertion of a preheating pipe 58 between the bobbin 15 from the yarn 14 to be crimped is unwound, and the dragging passageway 13. In said preheating pipe 58 it is possible to introduce a hot vapour or a hot gas by means of the injector 59. A possible liquid condensate is discharged through the mouth 60. It is to be understood that the pipe may be heated also electrically and in general the preheating of the thread 14 may be carried out 'by passing said thread over heating surfaces. These and other devices for preheating the yarn may be adapted to any embodiment of the remaining parts of the device.

To regularize the forwarding of the sliver of yarn accumulated in the stabilizing space 17, various devices can be used as shown in the examples illustrated in FIGS. 9 and l0 diagrammatically.

With reference to FIGURE 9, the stabilizing space 17 assumes a semi-circular configuration and is confined by guides of any convenient shape 61 sufficiently spaced apart to permit the insertion, into the sliver, of pins 63 carried by a wheel 62 at a controlled speed, those'pins thereby regulating the forwarding and the discharging of the sliver.

FIGURE 10 shows a similar device wherein the stabilizing space 17" is rectilinear and wherein the forwarding and the discharging are caused by a pin track 65 at controlled speed. A

FIGURES 12 and 13 crimped yarn.

Now some operating examples of the process according to the invention will be described with reference to the particular devices illustrated in the accompanying drawings.

show macrophotographs of '7 EXAMPLE 1 A nylon 6 thread of 1050 den., 70 filaments, having normal textile characteristics, is introduced into the apparatus of FIGURE 2, the essential details of which have the following critical dimensions:

The yarn is fed by a bucket with slanting roll at the linear speed of 400 meters per minute.

The injector pipe is supplied with compressed air at 8 kg./sq. cm. and is heated at 280 C.

As a stabilizing fluid, air at 185 C. was used.

Initially the formation of the sliver took place spontaneously.

The thread discharged at the end of the stabilizing zone shows a random three-dimensional Voluminization with rounded angles and each individual filament shows an aspect very similar to that of a filament of natural wool.

Said crimping is defined by the following parameters:

Voluminization factor 11.3 Crimp resistance, percent 90 Crimp ratio 1.15 Crimp number per cm 4 The expression Voluminization factor indicates the ratio between the apparent volume V1 of the yarn after Voluminization and the apparent volume V0 of the thread prior to Voluminization:

Voluminization factor=V1/V0 The volume is calculated by the formula:

m @l2-9000 n4-Count in denier where d=diameter of thread measured with the microscope (25 readings/determ.).

A portion of the crimped yarn obtained is subjected to a standard pre-tension of 0.55 mg./den., and its length is then measured. The same portion is then subjected to a standard tension of 111 nig/den., and the length of the yarn in the uncrimped state, thus produced, is also measured.

The expression crimp ratio indicates the ratio between the lentgh of the portion of yarn in the uncrimped state and that of the same portion of yarn, when subjected to the standard pre-tension.

The measuring of the crimped fibre is done with a standard pre-tension of 0.55 mg./ den.

For the measurement of the crimped fibre in the stretched state one applies a tension of 111 mg./den. standard.

By the expression resistance of crimping one indicates the permanence of the crimping of the thread after treatment with boiling water.

Said resistance is measured by determining on an individual filament the change of length caused by the flattening of the crimp when said filament is subjected to a treatment in boiling water for 30 seconds under the tension of 111 mg./ den. and allowed to dry in a conditioned atmosphere (21 C.-65% UR) under a tension of 0.55 mg./den.

The value of the resistance is given by the following ratio:

sion of 0.55 mg./den.

L1=length of uncrimped filament under standard tension of 111 mg./den.

L2=length of crimped filament under tension of 0.55

mg./den. after treatment in boiling water All of the standard tensions and the quantities mentioned are those provided in the BISFA specifications published in 1956: Mthodes pour la Dtermination de 1a Frisure des Fibres Synthtiques Base de Polyamides.

EXAMPLE 2 A nylon 6 thread of 1050 den., 70 filaments, is treated with the device of FIG. 2 having the dimensional data of Example 1, employing as a forwarding fluid steam at 5 kg./sq. cm. and a temperature of 180 C.

Stabilizing fluid: saturated steam at 120 C.

The crimping speed is 500 m./minute.

A thread is obtained whose characteristics are:

Voluminization factor 10 Crimp resistance, percent Crimp ratio 1.20

Crimp number per cm 4.5

EXAMPLE 3 A nylon 6 thread of 1260 denier, 68 filaments, is treated with the device of FIG. 2 having the dimensional data of Example 1, employing as a forwarding fluid air at the pressure of 8 kg./sq. cm. and at 300 and as a stabilizing fluid air at 180 C.

Linear feeding speed-500 m./minute.

The characteristics of the crimped thread are:

Voluminization factor 11 Crimp resistance, percent 98 Crimp ratio 1.15

Crimp number per cm. 4.5

EXAMPLE 4 Employing a device as in FIGURE 2, a nylon 6 thread of 1260 denier, 68 iilaments, is subjected to the crimping under the following conditions:

Mm. Diameter of injector pipe 10 1.25 Diameter of dragging passageway 13 1.5 Diameter of crimping chamber 11 6 Overall length of the crimping chamber 200 Length of the stabilizing zone 400 The thread is fed as in Example 1 at the speed of 400 m./minute. The injector pipe is fed with hot air at the absolute pressure of 8 kg./sq. cm. and at a temperature of 280 C. and the stabilization air at a temperature of 180 C.

The characteristics of the crimped yarn obtained are:

Voluminization factor 12 Crimp resistance, percent Crimp ratio 1.05 Crimp number per cm. 5

EXAMPLE 5 A nylon 6 thread of 420 denier, 80 filaments, is crimped with the device of FIG. 2 at a speed of 550 m./minute. The forwarding iiuid, the stabilizing uid and the dimensions of the device are the same as in Example 4.

The characteristics of the crimped yarn are:

Voluminization factor 13 Crimp resistance, percent 100 Crimp ratio 1.3 Crimp number per Acm 4.5

EXAMPLE 6 are heated electrically at the temperature of 180 C.

The injector nozzle is supplied with air at the pressure of 8 kg./sq. cm. and at the temperature of 300 C.

The feeding speed of the thread is 400 m./minute.

The cirmped yarn obtained has the following characteristics:

Voluminization factor 11 Crimp resistance, percent 86 Crimp ratio 1.12 Crimp number per cm. 4

EXAMPLE 7 A nylon 6 thread of 2520 denier, 136 filaments, is introduced into the apparatus of FIGURE 6 the essential details of which are critically dimensioned as follows:

Mm. Diameter of injector pipe 1.50 Diameter of dragging passage 13 2 Diameter of passageway 42 2.5 Diameter of crimping chamber 11 8 Length of crimping chamber 550 Length of stabilizing zone 350 Voluminization factor 9.5 Crimp resistance, percent 90 Crimp ratio 1.1 Crimp number per cm. 4.5

EXAMPLE 8 A nylon 6 thread of 3700 denier, 204 filaments, is introduced into the apparatus of FIGURE 6 whose essential details are equal to those of Example 7. The thread is fed at the speed of 250 m./minue. The two fluids introduced are the same as in the preceding example, omitting air for stabilization.

The characteristics of the crimped yarn obtained are:

Voluminization factor 9 Crimp resistance, percent 80 Crimp ratio 1.2

Crimp number per cm. 4

EXAMPLE 9 p A polyester thread of 600 denier, 100 filaments, is treated with the device as modied in FIGURE 7, the dimensions of the device shown in Example 1 being maintained as to the other details. The ovoidal portion of the crimping chamber has a maximum diameter of 10 mm. and a profile closely resembling an elliptic shape.

The thread is fed at the speed of 400 m./minute.

As a forwarding fluid, hot air is employed at the pressure of 10 kg./sq. cm., at the temperature of 350 C., and as a fixing fluid air at 180 C.

The crimping of the thread is defined as follows:

Voluminization factor 12.5

Crimp resistance, percent 95 .Crimp ratio 1.15

Crimp number per cm. 5.2

EXAMPLE 10 characteristics of the apparatus are like those described in Ex. 4 with reference to the corresponding parts of FIGURE 1.

The conditions of treatment are equalexcept for what has been specifically stated hereinbefore-to those of Example 4.

The characteristics of crimping are:

Voluminization factor 10 Crimp resistance, percent Crimp ratio 1.1 Crimp number per cm. 4

EXAMPLE l1 A nylon 6 thread of 1260 denier, 68 filaments, is crimped in the same apparatus and under the same conditions of Example 10 except that the ratio between the peripheral speed of the rollers 44 and 4S and the feeding speed is 1:60.

The characteristics of the crimped yarn obtained are:

Voluminization factor 12.6

Crimp resistance, percent Crimp ratio 1.15

Crimp number per cm. 4.5

EXAMPLE 12 The apparatus employed in this example is that of FIG. 11, the parts not illustrated, being those shown in FIGURE 2, with the dimensional characteristics as indicated in Example 4.

The preheating is carried out by means of hot air at the temperature of 180 C. and at atmospheric pressure.

The pipe 58 has 3 mm. diameter and 1000 m. length; the injector nozzle 59 injects hot air into said pipe while the thread is introduced thereinto.

The treated thread is nylon 6 of 1260 denier, 68 filaments, fed at the speed of 500 m. per minute.

The nozzle 10 is supplied with air at the pressure of 5 kg./sq. cm. and at the temperature of 260 C.

As a stabilizing fluid, saturated steam at atmospheric pressure is employed. The characteristics of the crimped yarn so obtained are as follows:

Voluminization factor 14 Crimp resistance, percent Crimp ratio 1.05 Crimp number per cm. 5.5

EXAMPLE 13 A thread of nylon 6 of 1260 denier, 68 filaments, is crimped with the same apparatus of Example 12. The conditions of treatment are also the same as those of Example 12.

However, for the pre-heating, superheated steam at the temperature of C. is employed at atmospheric pressure.

The characteristics of the crimped yarn obtained are:

Voluminization factor 12.5

Crimp resistance, percent 100 Crimp ratio 1.10

Crimp number per cm. 5

EXAMPLE 14 A thread of nylon 6 of 420 denier, 80 filaments, is crimped in the apparatus and under the conditions of treatment of Example 13.

The voluminized thread obtained has the following characteristics Voluminization factor 12.5

Crimp resistance, percent 100 Crimp ratio 1.15

Crimp number per cm 4.9 EXAMPLE 15 A nylon 6 thread of 2520 denier, 136 filaments is treated with the apparatus of Example 12 in which the preheating apparatus is constituted by an electrically heated pipe at a temperature of 220 C. and the diameter of which is constant from one end of the other, said pipe having a diameter of 3 mm. and a length of 1000 mm. The axis of the pipe shows a slight curvature, the radius f which is 3000 millimetres. The feeding fluid is air at pressure of 8 kg./sq. cm. at the temperature of 320 C.

The thread is fed at the speed of 350 m./minute.

The stabilizing iluid is saturated steam at atmospheric pressure.

The crimped thread obtained has the following characteristics:

Voluminization factor 11.3 Crimp resistance, percent 97 Crimp ratio 1.20

Crimp number per cm. 4.5

EXAMPLE 16 A nlyon 6 thread of 210 denier, 40 filaments, is treated in the apparatus and under the conditions of Example 12. The thread is fed at the speed of 800 m./min. The crimped thread obtained has the following characteristics:

Voluminization factor 12.8

Crimp resistance, percent 90 Crimp ratio 1.20

Crimp number per cm. 4.2

EXAMPLE 17 A sliver prepared and stabilized according to Example l is stretched out by subjecting it to a tension of 0.060 g./den. in an atmosphere at 90 C. and 60% relative humidity and is then wound up under said conditions on a bobbin.

After 2 days time the yarn is unwound in an atmosphere at 22 C. and 65% relative humidity and does not display any visible crimp.

The fabric manufactured with said yarn, after being immersed into a dyeing bath at 90 to 95 C., develops a crimping that displays the following characteristics:

Voluminization factor 9 Crimp resistance, percent 50 Crimp ratio 1.15

Crimp number per cm. 4

EXAMPLE 18 l A sliver prepared and stabilized according to Example is stretched by subjecting it to a tension of 0.075 g./den. in a room at 60 C. and 60% relative humidity and is wound up under the said conditions upon a bobbin.

After 6 days time the yarn is unwound in a room at 22 C. and 65% humidity and does not display any visible crimping.

The fabric manufactured with said yarn, after being treated with saturated steam at 130 C. at atmospheric pressure for 10 minutes time, develops a crimping that shows the following characteristics:

Volumiuization factor 11 Crimp resistance, percent 90 Crimp ratio 1.1

Crimp number per cm. 4

EXAMPLE 19 A sliver prepared and fixed according to Example is stretched by subjecting it to a tension of 0.120 g./den. in a room at 40 C. and 65 relative humidity and is wound up under the same conditions on a bobbin. After 2l days time the yarn is unwound in a room at 22 C. and 65% of humidity and does not display any visible crimpmg.

The fabric manufactured with said yarn, after being immersed into a bath of water at 90 C. for 60 minutes time, develops a crimping having the following characteristics:

Voluminization factor 8 Crimp resistance, percent 50 Crimp ratio 1.20

Crimp number per cm. 4.5

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The process for crimping synthetic filamentary material, comprising feeding the material into a passageway having a given cross-sectional area, causing a stream of gaseous medium to flow lengthwise of said passageway to draw said material therewith in substantially noncrimped condition through said passageway, transferring said medium and said material into a chamber communicating with said passageway and having a crosssectional area greater than said given area to cause slowing-down and expansion of said gaseous medium and crimping of the lamentary material in said chamber as a consequence of said slowing-down and expansion, then transferring said gaseous medium and crimped material into a stabilization zone down-stream of said chamber, and heat-stabilizing said material in its crimped condition.

2. The process of claim 1, in which said gaseous medium is heated to heat said material in said passageway and chamber prior to the heat-stabilizing processing of said material.

3. The process of claim 1, in which said crimped material is progressed down-stream of said crimping chamber in tow form and then heat-stabilized in said form by a gaseous medium, and in which said gaseous heat-stabilizing medium is exhausted from said material in the heatstabilization zone.

4. The process of claim 1, in which the said crimped and stabilized material is stretched at a tension from 20 to 200 g./den. at a temperature from 30 to 100 C., at a relative humidity from 60% to 70% and for a duration from .2 to 2 seconds, and then wound in substantially non-crimped condition.

5. An apparatus for crimping synthetic lamentary material, comprising an elongated passageway having a given cross-sectional area and an inlet and an outlet, means for continuously feeding non-crimped filamentary material into said inlet, blowing means for providing a stream of a gaseous medium lengthwise of said passageway for conveying said material through said passageway, a chamber having a cross-sectional area greater than said given area connected to said outlet for causing slowing-down and expansion of said gaseous medium and concurrent crimping of said material as said medium and material are transferred from said passageway into said chamber, a jacket disposed downstream of said chamber in communication with said chamber, to surround the crimped material, means for supplying a gaseous stabilizing fluid into said jacket in contact with the crimped material, and means for heating said jacket to cause the stabilizing fluid to heat-stabilize the crimped material.

6. The apparatus set forth in claim 5, having elongated guide means in said jacket for guiding said crimped material issuing from said chamber through said jacket, and means for exhausting said gaseous stabilizing fluid from said jacket.

7. Apparatus for crimping synthetic filamentary material as claimed in claim 5 having rectilinear guides in said jacket for guiding said material during heat stabilization, said guides being disposed about said material to produce frictional resistance to the movement of said material during heat stabilization.

8. Apparatus as claimed in claim 5 having additionally means for straightening the material after stabilization in order to wind the material on a suitable support.

9. Apparatus as claimed in claim 5 having additionally means for preheating said material prior to its introduction into said passageway.

10. In apparatus for crimping synthetic lamentary material, an elongate confined passageway, means for directing a stream of gaseous medium into said passageway to convey said material therealong and therethrough, said passageway having a first and al second portion of lesser and greater cross-sectional area, respectively, for causing slowing-down and expansion of said medium and concurrent crimping of said material as said medium and material pass from said rst to said second portion, and means for subjecting the crimped material to heat to heatstabilize the same.

11. In a process for promoting crimping of synthetic lamentary material which comprises feeding the material into and lengthwise of an elongate passageway by means of a gaseous stream flowing through said passageway, the steps of causing said gaseous stream to slow down and expand sharply after travelling a predetermined distance through the passageway by sharply increasing the crosssectional area of said lpassageway, thereby to cause said lamentary material to assume a crimped configuration concurrently with said slowing-down and expansion.

12. In a process for crimping synthetic lamentary material while said material is drawn along an elongate passageway by a stream of gaseous medium forcedly owing lengthwise of said passageway, the step of promoting sharp slowing-down and sideward expansion of said gaseous medium by transferring the gaseous medium into a stepped enlargement of said passageway, thereby causing crimping of the lamentary material because it follows concurrently the particles of said slowed-down and expanded gaseous medium.

References Cited UNITED STATES PATENTS 3,036,357 5/1962 Cook et al. 28*1 3,099,594 7/1963 Caines et al 28-1 X 3,111,740 11/1963 Stanley 28--1 3,121,935 2/1964 Shattuck et al 28-1 3,143,784 8/1964 Scott 28-1 X 3,152,379 10/1964 OsbOn 28-1 3,166,820 1/1965 Taul et al. 28-1 3,256,582 6/1966 Burleson 28 1 FOREIGN PATENTS 1,289,491 2/ 1962 France.

953,782 4/ 1964 Great Britain.

MERVIN STEIN, Primary Examiner. 

10. IN APPARATUS FOR CRIMPING SYNTHETIC FILAMENTARY MATERIAL, AN ELONGATE CONFINED PASSAGEWAY, MEANS FOR DIRECTING A STREAM OF GASEOUS MEDIUM INTO SAID PASSAGEWAY TO CONVEY SAID MATERIAL THEREALONG AND THERETHROUGH, SAID PASSAGEWAY HAVING A FIRST AND A SECOND PORTION OF LESSER AND GREATER CROSS-SECTIONAL AREA, RESPECTIVELY, FOR 